Search Publications
Chemical Abundances in an AGN Environment: X-Ray/UV Campaign on the Markarian 279 Outflow
Laor, Ari; Scott, Jennifer E.; Kriss, Gerard A. +11 more
We present the first reliable determination of chemical abundances in an active galactic nucleus (AGN) outflow. The abundances are extracted from the deep and simultaneous Far Ultraviolet Spectroscopic Explorer (FUSE) and Hubble Space Telescope (HST) STIS observations of Mrk 279. This data set is exceptional for its high signal-to-noise ratio, unb…
Stellar Populations across the NGC 4244 Truncated Galactic Disk
de Jong, Roelof S.; Ferguson, H. C.; Dalcanton, J. J. +12 more
We use the Hubble Space Telescope ACS to study the resolved stellar populations of the nearby, nearly edge-on galaxy NGC 4244 across its outer disk surface density break. The stellar photometry allows us to study the distribution of different stellar populations and reach very low equivalent surface brightnesses. We find that the break occurs at t…
Hubble Space Telescope Advanced Camera for Surveys Coronagraphic Observations of the Dust Surrounding HD 100546
Ford, H. C.; Illingworth, G. D.; Ardila, D. R. +3 more
We present HST ACS coronagraphic observations of HD 100546, a B9.5 star, 103 pc away from the Sun, taken in the F435W, F606W, and F814W bands. Scattered light is detected up to 14" from the star. The observations are consistent with the presence of an extended flattened nebula with the same inclination as the inner disk. The well-known ``spiral ar…
The WEBT Campaign on the Blazar 3C 279 in 2006
Lee, C. -U.; Nishiyama, S.; Mirabal, N. +77 more
The quasar 3C 279 was the target of an extensive multiwavelength monitoring campaign from 2006 January through April. An optical-IR-radio monitoring campaign by the Whole Earth Blazar Telescope (WEBT) collaboration was organized around target-of-opportunity X-ray and soft γ-ray observations with Chandra and INTEGRAL in 2006 mid-January, with addit…
Discovery of Pulsations and a Possible Spectral Feature in the X-Ray Emission from Rotating Radio Transient J1819-1458
Camilo, F.; Rea, N.; Chatterjee, S. +7 more
PSR J1819-1458 is a rotating radio transient (RRAT) source with an inferred surface dipole magnetic field strength of 5×1013 G and a 4.26 s spin period. We present XMM-Newton observations of the X-ray counterpart of this source, CXOU J181939.1-145804, in which we identify pulsations and a possible spectral feature. The X-ray pulsations …
GOODS 850-5: A z>4 Galaxy Discovered in the Submillimeter?
van Saders, Jennifer; Williams, Jonathan P.; Wang, Wei-Hao +2 more
We report an SMA interferometric identification of a bright submillimeter source, GOODS 850-5. This source is one of the brightest 850 µm sources in the GOODS-N but is extremely faint at all other wavelengths. It is not detected in the GOODS HST ACS images and only shows a weak 2 σ signal at 1.4 GHz. It is detected in the Spitzer IRAC bands …
Inverse Compton Scenarios for the TeV Gamma-Ray Emission of the Galactic Center
Hinton, J. A.; Aharonian, F. A.
The intense Compton cooling of ultrarelativistic electrons in the Klein-Nishina regime in radiation-dominated environments, such as that found in the Galactic center, may result in radically different electron spectra than those produced by synchrotron cooling. We explore these effects and their impact on the X-ray and γ-ray spectra produced in el…
The Moth: An Unusual Circumstellar Structure Associated with HD 61005
Henning, Thomas; Schneider, Glenn; Hines, Dean C. +11 more
We present the discovery of an unusual spatially resolved circumstellar structure associated with the ~90 Myr, nearby, G dwarf star HD 61005. Observations from the FEPS Spitzer Legacy Science survey reveal thermal emission in excess of expected stellar photospheric levels. Follow-up 0.1" resolution HST NICMOS coronagraphic images reveal scattered …
Mass Selection and the Evolution of the Morphology-Density Relation from z = 0.8 to 0
Kelson, D. D.; Demarco, R.; Rosati, P. +11 more
We examined the morphology-density relations for galaxy samples selected by luminosity and by mass in each of five massive X-ray clusters from z=0.023 to 0.83 for 674 spectroscopically confirmed members. Rest-frame optical colors and visual morphologies were obtained primarily from Hubble Space Telescope images. The visual morphologies ensure cons…
The Disk and Environment of a Young Vega Analog: HD 169142
Ménard, F.; Quirrenbach, A.; Hamaguchi, K. +15 more
We trace the disk of HD 169142 (A8 Ve) from 0.57" to 1.4" (~80-200 AU projected distance) in 1.1 µm scattered light with HST NICMOS coronagraphy. The azimuthally symmetric disk has a peak azimuthally medianed surface brightness (SB) of ~5 mJy arcsec-2 at 0.57" from the star, and drops ~r-3. This radial SB profile is con…